# Define here the models for your spider middleware
#
# See documentation in:
# https://docs.scrapy.org/en/latest/topics/spider-middleware.html

from scrapy import signals

# useful for handling different item types with a single interface
from itemadapter import is_item, ItemAdapter

from scrapy.http import HtmlResponse

from time import sleep


# class NeteaseSpiderMiddleware:
    # Not all methods need to be defined. If a method is not defined,
    # scrapy acts as if the spider middleware does not modify the
    # passed objects.

    #     @classmethod
    #     def from_crawler(cls, crawler):
    #         # This method is used by Scrapy to create your spiders.
    #         s = cls()
    #         crawler.signals.connect(s.spider_opened, signal=signals.spider_opened)
    #         return s
    #
    #     def process_spider_input(self, response, spider):
    #         # Called for each response that goes through the spider
    #         # middleware and into the spider.
    #
    #         # Should return None or raise an exception.
    #         return None
    #
    #     def process_spider_output(self, response, result, spider):
    #         # Called with the results returned from the Spider, after
    #         # it has processed the response.
    #
    #         # Must return an iterable of Request, or item objects.
    #         for i in result:
    #             yield i
    #
    #     def process_spider_exception(self, response, exception, spider):
    #         # Called when a spider or process_spider_input() method
    #         # (from other spider middleware) raises an exception.
    #
    #         # Should return either None or an iterable of Request or item objects.
    #         pass
    #
    #     def process_start_requests(self, start_requests, spider):
    #         # Called with the start requests of the spider, and works
    #         # similarly to the process_spider_output() method, except
    #         # that it doesn’t have a response associated.
    #
    #         # Must return only requests (not items).
    #         for r in start_requests:
    #             yield r
    #
    #     def spider_opened(self, spider):
    #         spider.logger.info('Spider opened: %s' % spider.name)
    #
    #
class NeteaseDownloaderMiddleware:
        # Not all methods need to be defined. If a method is not defined,
        # scrapy acts as if the downloader middleware does not modify the
        # passed objects.

        # @classmethod
        # def from_crawler(cls, crawler):
        #     # This method is used by Scrapy to create your spiders.
        #     s = cls()
        #     crawler.signals.connect(s.spider_opened, signal=signals.spider_opened)
        #     return s

    def process_request(self, request, spider):
        # Called for each request that goes through the downloader
        # middleware.

        # Must either:
        # - return None: continue processing this request
        # - or return a Response object
        # - or return a Request object
        # - or raise IgnoreRequest: process_exception() methods of
        #   installed downloader middleware will be called
        return None

    def process_response(self, request, response, spider):
        # Called with the response returned from the downloader.

        # Must either;
        # - return a Response object
        # - return a Request object
        # - or raise IgnoreRequest

        bro = spider.bro
        # 过滤指定的请求进行修改
        # spider爬虫对象
        if request.url in spider.models_urls:
            # print(request.url)
            bro.get(request.url)
            sleep(1)
            page_text = bro.page_source
            # print(page_text)
            # 所需要的对象进行修改

            new_response = HtmlResponse(url=request.url, body=page_text, encoding='utf-8', request=request)
            # print(new_response)
            return new_response
        else:
            # 其它请求对象
            response

        return response

    def process_exception(self, request, exception, spider):
        # Called when a download handler or a process_request()
        # (from other downloader middleware) raises an exception.

        # Must either:
        # - return None: continue processing this exception
        # - return a Response object: stops process_exception() chain
        # - return a Request object: stops process_exception() chain
        pass

    # def spider_opened(self, spider):
    #     spider.logger.info('Spider opened: %s' % spider.name)
